# Planned downtime


![left](./student-guide/diagram/28-Reasons-for-planned-system-unavailability-01-01.png)

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Planned downtime can disrupt operations, especially in a global enterprise that supports users in multiple time zones, up to 24 hours a day. In these cases, it is important to design a system to minimize planned disruptions. As shown in the diagram on the slide, reasons for planned downtime include routine operations, regular maintenance, and new deployments. 

Routine operations are frequent maintenance tasks, including backups, performance management, user and security management, and batch operations.

Periodic maintenance is sometimes required, such as installing patches or reconfiguring the system to update databases, applications, operating systems, middleware, or networks.

A new deployment describes a major upgrade to the hardware, operating system, database, application, middleware, or network. It is important to consider not only the timing of the upgrade, but also the impact that the change may have on the entire application.